An implant may be used as a delivery vehicle for radiation in various circumstances. An implant including a radiation source may have a structural or other function in addition to its radiation delivery function. For example, an implant including a radiation source may be used to respond to a spinal pathology and as part of a cancer treatment. Some implants may also have a radiation delivery function alone, such as brachytherapy devices. By way of further example, some implants may be interbody spinal implants or a vertebral body replacement implants. Implants classified as vertebral body replacement implants may include implants used in association with corpectomy or vertebrectomy procedures to stabilize spinal structures. Removal, or excision, of a vertebra may be referred to as a vertebrectomy. Excision of a generally anterior portion, or vertebral body, of the vertebra may be referred to as a corpectomy. If only a portion of a vertebral body and adjacent discs are removed and replaced, the procedure may be called a hemi-vertebrectomy. Any of these types of implants or other implants may include a suitable radiation source. It may be advantageous in some circumstances to provide a way of restricting or even stopping the emission of radiation from an implant that includes a radiation source. Some embodiments of an improved device may include the capability to emit a therapeutically effective amount of radiation for a period of time and then to reduce or shut off the radiation. Some embodiments of an improved device may be operable to reduce or shut off radiation emission without further surgical intervention.